This adds some new `data/text/` files, which are the new home for
item/move/ability descriptions, as well as in-game messages, in one
place for ease of translation.
`BattlePokedex` is now `Pokedex`, `BattleItems` is now `Items`, etc.
I also renamed `Movedex` to `Moves` and `Statuses` to `Conditions`.
`TypeChart` isn't `Types` yet, because unlike the others, it's not
indexed by ID. That should probably be fixed one day.
- `Modded[Effect]Data` are now correctly defined: they must either have
`inherit: true` and be partial, or not have `inherit: true` and be a
complete `[Effect]Data` entry
- `id` is no longer allowed; instead, it's calculated directly from
`toID(name)`. The one exception, Hidden Power, gets a `realMove`
property to track this (it's still used to set `.id`, though;
TODO: really fix it properly).
- `num` is still required in `data/pokedex.ts` (dex number),
`data/moves.ts` (move index number, for Metronome), and
`data/items.ts` (minisprite sprite-sheet location). It's still not
required for mod-only items and moves.
- `num` is no longer allowed for PureEffects (in `statuses.ts`) where
it's always been meaningless.
- `color` and `heightm`, being completely flavor, are still not
required for `pokedex.ts` in mods. They're still required in the base
pokedex.
